key index

General steps for MySQL optimization: 1. Run the show status command to check the execution efficiency of various SQL statements. Show status provides the status information of the msyql Server Generally, we only need to know the commands

First, the preface MySQL InnoDB, support transaction and row level lock, can use row lock to handle the business such as user's mentioning. The use of MySQL locks sometimes deadlock, to do a good job of deadlock prevention. Second, MySQL row-level

One, indexing base usage 1. Create an index You can create an index when you execute a CREATE TABLE statement, or you can add an index to a table by using either CREATE INDEX or ALTER TABLE alone. 1>alter TABLE ALTER table is used to create a

The pros and cons of 8.4.5 indexes and how to determine whether an index is needed I believe readers know that indexing can greatly improve the efficiency of data retrieval, so that query executes faster, but probably not every friend knows that

IndexAn index is an object in a relational database that is used to hold each record, and the main purpose is to speed up the reading speed and integrity checks of the data. Indexing is a highly technical and demanding task. Generally in the

0. The conceptual index of an index is a special kind of file (an index on a InnoDB data table is an integral part of a table space), and they contain reference pointers to all records in the datasheet. Like a book in front of the directory, can

IndexAn index is an object in a relational database that is used to hold each record, and the main purpose is to speed up the reading speed and integrity checks of the data. Indexing is a highly technical and demanding task. Generally in the

MYSQL (iii)The previous chapter to everyone said is the database view, stored procedures and so on, this chapter is mainly about indexing, as well as indexing considerations, if you want to see the previous article, the URL is as follows:

--unique Unique index, clustered clustered index, nonclustered nonclustered index. The primary key is unique, so a primary key is created and a unique index is created for that field. SQL Server defines the primary key as a clustered index by

The following articles mainly describe the creation and deletion of MySQL databases, as well as the detailed parsing of indexes and changing actual table statements. If you are also popular with MySQL databases, you can click the following article

You can CREATE an INDEX in the create table statement, or use the create index or alter table statement to add an INDEX to the TABLE. You can use alter table or drop index statements to delete indexes.(1) Use the alter table statement to create an

    I. Index Introduction 1.1 index creation Syntax: Create uniuqe | bitmap index . ON . (| ASC | DESC, | ASC | DESC ,...) TABLESPACE STORAGE LOGGING | NOLOGGING COMPUTE STATISTICS NOCOMPRESS | COMPRESS NOSORT | REVERSE PARTITION | global

Index (learning notes), index learning notes The tablespace can be omitted. B-Tree Index Reverse Key Index Function Index Bitmap Index Delete Index   B-Tree Index Example 1,Create a table and use the PL/SQL data generator to import 0.1 million

Msdn magazine megal 2003 (Advanced T-SQL) Download the original code: storedprocedures.exe (0000kb) This document assumes that you are familiar with T-SQL. 　 Summary The automation during design accelerates coding and ensures that all processes

Common Database interview questions and database questions Paradigm 1: Each column in a database table is a basic data item that cannot be further divided. values or duplicate attributes are not allowed. For example, if a table contains a phone

Create and delete IndexesYou can create an index in the create table statement, or use the create index or alter table statement to add an index to the table. You can use alter table or drop index statements to delete indexes.(1) Use the alter table

MySQL (III), mysqlMYSQL (III) The previous chapter describes database views, stored procedures, and other operations. This chapter focuses on indexes and index considerations. If you want to read the previous article, the url is as follows: Full

Mysql creates an index and deletes an index bitsCN.com You can CREATE an INDEX in the create table statement, or use the create index or alter table statement to add an INDEX to the TABLE. You can use alter table or drop index statements to delete

Tag Description format length value Description 4F Application Identifier (AID) B Registration app provides trademark identification (RID) and private identifier extensions: a000000333

Transferred from http://talentluke.iteye.com/blog/1843868 Excerpt from http://book.51cto.com/art/200906/132406.htm the pros and cons of 8.4.5 indexes and how to determine whether an index is needed I believe readers know that indexing can greatly